Autosave don’t work in 2.8
In Preferences > Save and Load > Auto Save,  do you have the Auto Save Temporary Files option checked ?


Next check in Preferences > File Paths > Data > Temporary Files, left click the folder icon to see if you have any .blender files saved at this location.


This is what i have in my Temp folder:


Note that holding down the Alt key and left clicking that little folder icon will take you directly to the location on your hard drive from where you can drag one of the saved  .bland files onto your desktop and then open it again in Blender.